Sodium permanganate

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

See the read-across report attached in Section 13.

Reason / purpose for cross-reference:

read-across source

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

3 other: mg Mn/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: Dissolved

Basis for effect:

other: Survival

Remarks on result:

other: Soft water

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

8.6 other: mg Mn/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: Dissolved

Basis for effect:

other: Survival

Remarks on result:

other: Moderately hard water

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

13.7 other: mg Mn/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: Dissolved

Basis for effect:

other: Survival

Remarks on result:

other: Hard water

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

See the read-across report attached in Section 13.

Qualifier:

no guideline followed

Principles of method if other than guideline:

Sensitivity of H.azteca to Mn was determined with 7-day-old animals in acute 96-h tests. Tests were run at three levels of water hardness (soft, moderately hard and hard).

GLP compliance:

not specified

Analytical monitoring:

yes

Details on sampling:

- Concentrations: Concentration of Mn and major cation and ions (Na, K, Ca, Mg, Cl, SO4) were measured for each test solution. Concentration was determined at test termination.
- Sampling method:Test solutions with the highest and lowest Mn concentrations for each type of water was also sampled and preserved after 96-h to assess changes in concentrations that occurred during the tests.
- Sample storage conditions before analysis: Preserved by adding 1% (v:v) ultrapure NHO3.

Test organisms (species):

other aquatic crustacea: H.azteca

Details on test organisms:

TEST ORGANISM
- Common name: Scud
- Source: Known-age H.azteca were obtained for testing from in-house cultures using methods similar to those of Tomasovic et al. (1995).
- Age at study initiation : < 24-h old animals
- Method of breeding: Mixed caged animals from the cultures were placed on 1-mm mesh transferred to 355-µm mesh sieves in 8-L plastic containers with 6L of MH5 water. Approximately 500 adults animals placed on each sieve produced around 600 young in 24h. T
- Feeding during test: Not fed during the test.



ACCLIMATION
- Acclimation period: The young H.azteca were held for 6 days with water exchanged (60%) every other day, at which time additional food was added.
- Type and amount of food: A small amount of Tetrafin was added to the sieves for food. After 24h, the sieves were again agitated and transferred to a container with 6L of freshwater to which 45mL of S. capricornutum algae and 25 ml of YCT had been added as food for the young.

Test type:

static

Water media type:

freshwater

Total exposure duration:

96 h

Post exposure observation period:

Not reported

Hardness:

SW = soft water = 26 mg/L
MH4= four-salt moderately hard water = 92 mg/L
H4= four-salt hard water = 184 mg/L

Test temperature:

25°c

pH:

8.0-8.4

Dissolved oxygen:

Not reported

Salinity:

Not reported

Nominal and measured concentrations:

2.5, 5, 10, 20, 40, 80 mg Mn/L - Nominal Concentration

Details on test conditions:

Test System
Test vessel: plastic cup. The plastic cup consisted of a 1.5-cm2 piece of Nitex netting.
- Type :closed
- fill volume: 30 ml
- Aeration: yes
- No. of organisms per vessel:10
- No. of vessels per concentration (replicates):5
- No. of vessels per control (replicates):5


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: See table 1. Sodium bromide (1 mg/L) was added to the MH5, H5 and SW waters to bolster survival of H. azteca . Each water was used to prepare the most concentrated Mn solution and was also used as the dilulent and control in their respective test.
- Intervals of water quality measurement: Alkalinity and pH of all test solutions were measured at test initiation (titration with H2SO4 for alkalinity, pH electrode and meter for pH).

OTHER TEST CONDITIONS
- Photoperiod: 16 h light: 8 h dark

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Survival was the endpoint in test with tH.azteca

TEST CONCENTRATIONS
Manganese solution for the test were prepared 24 h prior to test initiation by adding MnCl2.4H2O to the waters with a targeted nominal concentration of 89 mg Mn/L. This solution was then serially diluted (0.5 x) to produce six Mn concentrations (80, 40, 20, 10, 5 , 2.5 Mn/L.

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

3 other: mg Mn/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

dissolved

Basis for effect:

other: Survival

Remarks on result:

other: Soft water (see table 1)

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

8.6 other: mg Mn/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

dissolved

Basis for effect:

other: Survival

Remarks on result:

other: Moderately hard (see table 1)

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

13.7 other: mg Mn/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

dissolved

Basis for effect:

other: Survival

Remarks on result:

other: Hard water (see table 1)

Details on results:

Survival of H.azteca in control waters ranged between 90 and 100%.

Manganese was toxic to H.azteca and increased water hardness significantly reduced toxicity.Manganese was more toxic to H.azteca in soft water (SW), followed by moderately hard (MH5) and hard (H5) waters, and lethal concentrations (lC50s) were significantly different from one another. In the current. the LC50 values for H.azteca were 3.0 and 8.6 mg Mn/L for waters with hardness of 26 and 80, respectively. These values bracket the LC50 of 4.2 Mn/L reported by Stubblefield et al (1997).

Reported statistics and error estimates:

Calculations of LC50 values were performed with the trimmed Spearman Karber method (Hamilton et al. 1977).

Conclusions:

LC50s determined for H.azteca progressively increased from 3.0 to 8.6 to 13.7 mg Mn/L in soft, moderately hard, and hard waters, respectively.

Description of key information

LC50s determined for MnCl2 in H.azteca progressively increased from 3.0 to 8.6 to 13.7 mg Mn/L in soft, moderately hard, and hard waters, respectively.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

LC50

Effect concentration:

3 mg/L

Additional information

Sensitivity of H.azteca to MnCl2 was determined with 7-day-old animals in acute 96-h tests. Tests were run at three levels of water hardness (soft, moderately hard and hard). The study was awarded a reliability score of 2 in accordance with the criteria set forth by Klimisch et al. (1997).

Under the conditions of the study the LC50s determined for MnCl2 in H.azteca progressively increased from 3.0 to 8.6 to 13.7 mg Mn/L in soft, moderately hard, and hard waters, respectively.